Lecture 1: Overview of CSCI 485 Notes: I presented parts of this lecture as a keynote at Educator’s Symposium of OOPSLA Shahram Ghandeharizadeh Associate Professor Computer Science Department University of Southern California

Logistics Required text book: Required text book:  Database System Concepts, Silberschatz, Korth & Sudarshan. Available in the bookstore.  Please start to read Chapter 6 and Section 7.1 for the next lecture Pre-req for the course: Pre-req for the course:  CS201: Data Structures  Knowledge of an object-oriented programming language such as C++, Java, C#

Instructor Details Dr. Shahram Ghandeharizadeh Office: SAL Phone: Office Hours: Tuesday: 12:30 to 2 pm Thursday: 4 to 5 pm Class URL:

Outline Motivation for DBMS Motivation for DBMS An outline for the course material An outline for the course material Grading: Assignments and projects Grading: Assignments and projects

Database Management Systems (DBMS) Used almost on a daily basis for either individual or business use. Used almost on a daily basis for either individual or business use. Relational database vendors were one of the fastest growing sectors during the.COM boom! Relational database vendors were one of the fastest growing sectors during the.COM boom!

DATABASE & DBMS Database: An integrated collection of data, usually stored on secondary storage, typically describing the activities of one or more related organizations. Database: An integrated collection of data, usually stored on secondary storage, typically describing the activities of one or more related organizations. Database management system (DBMS): A collection of software/programs designed to assist in maintaining and utilizing large collections of data. Database management system (DBMS): A collection of software/programs designed to assist in maintaining and utilizing large collections of data.

BEFORE DBMS Data User 1 User 2 Application programs

Data managed by DBMS AFTER DBMS User 1 User 2 DBMS Application programs

WHY A DBMS? 1. Reduced application development time 2. Data independence: Application programs not dependent on data representation and storage details 3. Data sharing: data is better utilized (discovered and reused), redundancy of data is minimized 4. Data integrity and consistency: one may enforce consistency constraints on data, e.g., number of seats sold ≤ number of seats on the plane × Centralized control: DBA tunes the database to balance user's needs 6. Security: mechanisms to prevent unauthorized access. These mechanisms are based on content instead of file-oriented approach. 7. Concurrency control: avoids undesirable race conditions that arise with simultaneous access/updates to data 8. Crash recovery: ensures the integrity of data in the presence of failures

DBMS ARCHITECTURE User 1 User n … Conceptua l schema Physical data DB DBMS

Data Models Conceptual Logical Physical

Data Models (Example) Build a database of all my assets for licensing and royalty collection

Data Models Conceptual Logical Physical

Challenges Conceptual Logical Physical Abstraction, Inheritance, Encapsulation Reduction to tables with minimal: data duplication, potential for data loss and update anomalies Effective use of a DBMS, management of mismatch between tables and OO constructs, Index structures, CC & Crash recovery, Optimization techniques

Challenges Conceptual Logical Physical E-R data model Relational Data model, SQL, Relational Algebra Different kinds of storage, A DBMS architecture, Index structures, CC & Crash recovery, Optimization techniques, Techniques to build a DBMS 5 Normal Forms

Relational DBMS Why? Why?  Performance!  Reduced application development time  Use of SQL makes access to data more uniform:  Software modularity,  Extensibility

Challenge 2 Two ways to teach this course: Two ways to teach this course:  How to implement a DBMS?  Protocols to realize atomic property of transactions  How to use a DBMS?  Setup a web server with a database and build a shopping bag Key difference: discussion at both the logical and physical levels Key difference: discussion at both the logical and physical levels Both require use of OO constructs Both require use of OO constructs

Grading Midterm 1: 35% Midterm 1: 35% Midterm 2: 35% Midterm 2: 35% Assignments: 15% Assignments: 15% Project: 15% (Questionable due to lack of a TA) Project: 15% (Questionable due to lack of a TA)

Assignments (15%) Social networking sites: Social networking sites:  Visit myspace.com and sign-up.  Become my friends – whether you like it or not  Become my friends – whether you like it or not  Use the bulletin capability to communicate. Objective is to understand the functionality of the bulletin board. First message might be a quick note about why you have signed up for csci 485.  Homework 1: Write a description of the bulletin board and its functionality.  Homework 2: Draw the ER diagram for the web site, focusing on its Bulletin board.  Homework 3: Reduce the ER diagram to a collection of tables.

Project (15%) Part 1: Implement a Bulletin board using a centralized database management system. Part 1: Implement a Bulletin board using a centralized database management system. Part 2: Extend your implementation to a database partitioned across multiple servers. Part 2: Extend your implementation to a database partitioned across multiple servers.